T14740 fails in debugged compiler

--- parser/should_fail/T14740.run/T14740.stderr.normalised	2018-12-30 16:06:27.120170052 +0000
+++ parser/should_fail/T14740.run/T14740.comp.stderr.normalised	2018-12-30 16:06:27.120170052 +0000
@@ -1,4 +1,5 @@
+ghc: panic! (the 'impossible' happened)
+  (GHC version 8.7.20181230 for x86_64-unknown-linux):
+	ASSERT failed! file compiler/types/TyCoRep.hs, line 911
 
-T14740.hs:5:7:
-     Expecting a lifted type, but ‘(# #)’ is unlifted
-     In the type signature: x :: ((# #)) => ()
+Please report this as a GHC bug:  https://www.haskell.org/ghc/reportabug

Trac metadata

Trac field	Value
Version	8.6.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	high
Resolution	Unresolved
Component	Compiler (Type checker)
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	goldfire, simonpj
Operating system
Architecture